Wash and dry the sweet potatoes. You can either leave the skins on or you can also peel them.
Cut the sweet potatoes into cubes, whatever size you want and place them into a bowl. Note, the bigger the cubes, the longer they will need to fry. I like mine to be on the smaller side (about 1/4in by 1/4in).
Drizzle the sweet potato cubes with olive oil and toss them until well covered.
Sprinkle the salt, pepper, garlic powder, rosemary, and sweet paprika on the top of the cubed potatoes. Toss until all the potatoes are evenly coated.
Transfer the potato cubes into the air fryer for frying. Double check your machine manufacturer's instructions for detailed info on frying time as they usually have a booklet with frying times in there.
I have the T-Fal Actifry Electric Fryer and for this amount of potatoes the frying time was 45 minutes.
Once the potatoes are done, transfer them to a serving bowl for serving.
Mayo Ketchup Sauce
Combine the mayo, ketchup and garlic powder (if using) and mix well together.
Notes
The air fryer I have, has a rotating bowl inside, so the potato cubes are constantly moving and get evenly fried. I don't have experience with other air fryers, but you might need to flip the potato cubes for best results.